Applying standards to readymade spectacles used in low-resource countries

To test the applicability of standards of appearance, construction, optical quality and performance, and durability proposed for readymade spectacles to be used by eye care programs in low-resource countries.

Orders of readymade spectacles were procured from three suppliers by an eye care program in Timor-Leste. Feedback regarding quality was given to one supplier before placing subsequent orders. Spectacles were randomly selected from each order: 250 for powers +3.00 to -3.00 diopter sphere (DS), being of most interest to eye care programs, and 100 from +/-3.50 DS and +/-4.00 DS powers combined. An additional 100 spectacles of infrequently dispensed higher powers were sourced and tested. Every appliance was assessed by a single investigator against items of the proposed standards. A pass or fail was determined for each appliance for each standard. Based on this experience, the utility of application of the proposed standards was appraised.

With the exception of impact resistance, it was possible to test spectacles against all proposed standards. Cost was no predictor of quality. Of a sample of high power spectacles, 65% failed at least one standard. For low power samples, as few as 2.8% failed. Quality improved with feedback to the supplier.

Standards testing can be accommodated with a combination of manufacturer/supplier batch testing and program evaluation of spectacle units. With limited skill and equipment (lensmeter, pupillary distance rule, and caliper), and an ongoing interaction with its supplier, an eye care program can apply the proposed standards and influence the quality of spectacles supplied.